SDF — Solar-aware distributed flow in wireless sensor networks

Abstract

Energy is the most limiting factor in wireless sensor networks. Harvesting solar energy is a feasible solution to overcome the energy-constraint in some applications. It enables a theoretically infinite network lifetime, sustaining a mode of operation termed energy neutral consumption rate The challenge arises, how can the harvested energy be utilized to maximize the performance of the sensor network. Considering a field monitoring application the performance is measured as the sustained sampling rate of the sensors. Maximizing the sampling rate needs to take the spatio-temporal distribution of load and energy into account, to prevent the overloading of nodes. In [1] they introduced a optimal, theoretical solution based on perfect global knowledge. In this paper we propose the solar-aware distributed flow (SDF) approach. SDF enables each node to predict the harvested energy, calculate a sustainable flow and control its local neighborhood. To the best of our knowledge it is the first practical solution. Extensive simulations confirmed that SDF achieves over 80% of the theoretical optimum, while introducing negligible overhead.

C-SDF: Practical solar-aware distributed flow control

“…SDF [3] introduced the first approach for flow control rely ing on local knowledge only. However, real-world applicability and the interaction with routing protocols remained unclear.…”

“…Later, we introduced SDF [3]. To change the rate assignment nodes need only contact their children in the routing tree.…”

“…And it has lead to the introduction of different flow control mechanisms [3], [4], enabling nodes to control their sampling rate and the flow they need to forward for remote nodes. Fan et al [4] provided the first centralized and distributed solution.…”

“…Hence, the approach is not applicable to real networks. In 2011, we have introduced the solar-aware distributed flow (SDF) approach [3] as the first practical flow control heuristic. In SDF nodes distribute control messages only to their children in the routing tree.…”

A Metropolitan-Scale Testbed for Heterogeneous Wireless Sensor Networks to Support CO2 Reduction

“…2). By using energy-efficient algorithms and an adaptive sampling rate [11], we are able to allow almost perpetual network operation even though the nodes are battery powered. A base station located in the city center collects all measurements as the trams pass by.…”